Gas discharge panel

ABSTRACT

A gas discharge panel comprising at least one exhaust tube which extends along an edge of the panel. A slot-like aperture, which mainly extends in the longitudinal direction of the exhaust tube, or a number of separate apertures, are present in the wall of the exhaust tube.

United States Patent De Vries et al.

GAS DISCHARGE PANEL Inventors: Gerhard Heinrich Friedrich De Vries; Petrus Franciscus Antonius Haans, both of Emmasingel, Eindhoven, Netherlands U.S. Philips Corporation, New York, NY.

Assignee:

Filed: Dec. 19, 1973 Appl. No.: 426,255

Foreign Application Priority Data Jan. 15, 1973 Netherlands 7300553 US. Cl. .Q 313/220, 313/188 Int. Cl. H0lj 61/30 Field of Search 313/220, 188

[56] References Cited UNITED STATES PATENTS 3,499,167 3/1970 Baker et al. 3l3/22O X Primary Examiner]ohn Kominski Assistant ExaminerDarwin R. Hostetter Attorney, Agent, or FirmFrank R. Trifari; Carl F. Steinhauser [57] ABSTRACT A gas discharge panel comprising at least one exhaust tube which extends along an edge of the panel. A slotlike aperture, which mainly extends in the longitudinal direction of the exhaust tube, or a number of separate apertures, are present in the wall of the exhaust tube.

4 Claims, 3 Drawing Figures 2 I t g GAS DISCHARGE PANEL The invention relates to a gas discharge panel comprising a base plate, a front plate and an exhaust tube which is in open communication with at least one space which is present between the base plate and the front plate.

Such a gas discharge panel is known from the US. Pat. No. 3,499,167. The gas discharge panel described in said Specification comprises an exhaust tube which is provided at one of the corners of the panel or at some distance therefrom between the base plate and the front plate. Such a construction presents the advantage that the depth of the panel is determined only by the distance from the base plate to the front plate. Actually this is not the case in other known constructions in which the exhaust tube starts from the base plate of the panel. Such a construction is known, for example, from Dutch Pat. application 7,003,971.

The projection of the exhaust tube in the known gas discharge panels, however, is experienced as being very detrimental. In particular upon assembling such a panel or during transport the exhaust tube can easily develop a leak or even break by impact.

It is an object of the invention to provide a gas discharge panel of the type described in the first paragraph in which the said drawback is avoided.

For that purpose, a gas discharge panel according to the invention is characterized in that the exhaust tube extends along an edge of the gas discharge panel.

With such an arrangement of the ,exhaust tube a gas discharge panel is obtained which has no vulnerable A favourable embodiment of a gas discharge panel according to the invention is obtained if the exhaust tube has a number of separate apertures instead of one slot-like aperture. These apertures have been provided in the wall of the exhaust tube by a simple operation, such as drilling, or by means of a metal mandrel which is heated at a high temperature. In addition to the advantage of a simple operation, a mechanically particularly rigid construction is obtained.

A particularly favourable embodiment according to the invention is obtained in a gas discharge panel which has an exhaust tube on at least two edges which are preferably located opposite to each other. During rinsing, an ionizable gas may be admitted to the gas discharge spaces of the panel via one exhaust tube, while simultaneously the undesired residual gases are repelled from the panel via the other exhaust tube. In this manner a gas discharge panel according to the invention is rinsed not only rapidly but also particularly effectively. Such a construction moreover presents the possibility of rinsing a number of gas discharge panels simultaneously by incorporating them in one pumping circuit, either in series or in parallel.

The invention willbe described in greater detail with reference to'the accompanying drawing which is not drawn to scale and in which:

FIG. 1 is a cross-sectional view taken at right angles to the axis of the exhaust tube of a gas discharge panel projecting parts. Moreover, such an arrangement provides thepossibility of a mechanically rigid connection between the exhaust tube and the gas discharge panel since the surface of the exhaust tube to be connected to the panel can now extend substantially throughout the length of the exhaust tube.

The exhaust tube of a gas discharge panel according to the invention preferably has a slot-like aperture which extends mainly in the longitudinal direction of the tube. With such an aperture, a large substantially equipotential flow surfaceis obtained during the evacuation and filling with gas of the gas discharge panel. As compared with the known gas discharge panels which are evacuated and filled with gas from one point, the gas discharge panel according to the invention exhibits considerably shorter pumping paths. Such a reduction in the length of the pumping paths is not expressed only in a shorter rinsing time of the gas discharge panel, but the discharge spaces which are more remote from the aperture of the exhaust tube are also better involved in the rinsing process. Rinsing is to be understood to mean herein a process in which evacuation and filling with gas of the gas discharge panel is repeated several times successively until all the gas discharge spaces no longer contain any detrimental residual gases any longer. In particular In the larger panels such rinsing is a timeconsuming process since, in order to minimize crosstalk between adjacent gas discharge spaces, the communication channels between the spaces have a very small cross-section and hence a small flow capacity. It is thus of importance to hamper the accessibility to the gas discharge spaces as little as possible. In that respect, the slot-like aperture which may be provided in the exhaust tube, for example, by a sawing or grinding operation, provides a very positive contribution.

according to the invention;

FIG. 2 is a perspective view of an embodiment of an exhaust tube; and, FIG. 3 is a plan view of a preferred embodiment of a gas discharge panel according to the invention.

The gas discharge panel shown in FIG. Icomprises a base plate 1, a light-permeable front plate 2 and an intermediate plate 3 which has apertures 4, said plates consisting of insulating material. A gas discharge can be produced in one or more of the holes 4 by means of a number of electrode systems 5 and 6 which cross each other. The holes 4 are in open communication with each other by means of a number of channels 7 which open into a cavity 8. Channels 7 can be obtained, for example, by superficially etching away the part of the electrodes 5 which is present in the interior of the gas discharge panel. An exhaust tube 9 in whichan axial slot-like aperture 10 is sawn which also opens into the cavity 8 is present along one edge of the panel. As shown in FIG. 2, the slot-like aperture may also be replaced by a number of holes which are drilled in the wall of the exhaust tube 21. The exhaust tube ,9 is secured to the panel and the interior of the panel is sealed from the atmosphere in a vacuum-tight manner by means of a glass frit 11 or other means known for that purpose.

The gas discharge panel shown in FIG. 3 again comprises a light-permeable front plate 32 which is partly broken away in the drawing, a base plate 31 and an intermediate plate 33 having apertures 34. On the inside of the front plate an electrode system 36 is embedded which crosses an electrode system embedded in the base plate so as to produce a gas discharge in one or more of the discharge spaces 34 by means of said electrodes. The exhaust tubes 38 and 39 are present along two oppositely located edges of the gas discharge panel and are in open communication with each other via slot-like apertures 40 and the channels 37 present in the two exhaust tubes. The gas discharge panel is filled with an inert gas which is admitted via the exhaust tube 38. During the admission the undesired gases are rinsed out of the discharge spaces of the panel via the channels 37 and the exhaust tube 39, after which both exhaust tubes are sealed as is denoted by 41.

What is claimed is:

l. A gas discharge panel comprising a base plate, a front plate and an exhaust tube which is in open communication with at least one space which is present be tween the base plate and the front plate, said exhaust tube extending along an edge of the gas discharge panel.

comprising an exhaust tube on at least two edges.

l l k l 

1. A gas discharge panel comprising a base plate, a front plate and an exhaust tube which is in open communication with at least one space which is present between the base plate and the front plate, said exhaust tube extending along an edge of the gas discharge panel.
 2. A gas discharge panel as claimed in claim 1, wherein the open communication between the exhaust tube and the said space is formed via a slot-like aperture extending mainly in the longitudinal direction of the exhaust tube.
 3. A gas discharge panel as claimed in claim 1, wherein the open communication between the exhaust tube and the said space is formed via a number of apertures which are present in the wall of the exhaust tube.
 4. A gas discharge panel as claimed in claim 1 further comprising an exhaust tube on at least two edges. 